Use of intraocular lenses or artificial lenses is widely known for correcting impairment of vision. They are mainly designed to correct aphakia following cataract extraction.
As a rule, these lenses comprise an optic body and supporting elements, shape, dimensions and configuration of which depend on physical characteristics of the material.
Often following implantation of the known lenses, there arises the problem associated with a possibility of an uncontrollable displacement of the optic portion that results in impairment of ocular refraction, iridal dispigmentation and as a sequence, in the development of secondary pigmental glaucoma.
Furthermore, mechanic injury of the surrounding tissues induced by displaced optic portion, results in impairment of their trophism, washing out of proteins and their deposition on the optic portion of artificial lens (AL) that means loss of its optic characteristics.
Various attempts were earlier Undertaken to reduce post operative complications through preventing uncontrollable displacement of the optic portion following its implantation caused by the action of capsular forces occuring because of discrepancy between the dimensions of the AL optic portion and the capsule due to outgrowth of lens masses in case of their incomplete extraction during surgery. Therefore, when sufficiently large displacement occurs in a part of patients, there are observed iridal injury and dispigmentation resulting in the development of secondary glaucoma.
Earlier, the authors of this invention had developed the AL (RF patent No.2097006 granted to Fedorov et al.) manufactured from elastic biologically inert material and comprising optic portion and diametrically disposed support elements in the form of truncated disc, distal portions of supporting elements being manufactured centrally concave and their frontal surfaces having grooves disposed at right angle to vertical axis.
Said grooves provide on supporting elements, permitted to exclude negative effect of those portion of capsular forces that are directed at right angle to said grooves.
However, it was found that this AL was efficient only in those cases when capsular forces caused by contraction of ligaments of Zinn were directed strictly perpendicular to the grooves. Taking into consideration the fact that capsular forces can act in any directions, then in these cases, this results in uncontrollable displacement of the optic portion due to bending of support elements as affected by such forces as well as in uncontrollable displacement of one or both haptic elements.
There is known the U.S. Pat. No. 5,476,514 comprising optic body and haptic on which grooves parallel to vertical lens axis, are provided and presence of such grooves in this AL is directed at accomplishing controllable displacement of optic portion as affected by capsular forces that promotes accomodation of the eye following surgery.
Accordingly, need exists in providing AL for implantation following extraction of cataract of any etiology as well as for implantation into the aphakic eye.